rtc: rtc-wm831x: use devm_rtc_device_register()

devm_rtc_device_register() is device managed and makes cleanup
paths simpler.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/rtc-wm831x.c b/drivers/rtc/rtc-wm831x.c
index 2f0ac7b..8d65b94 100644
--- a/drivers/rtc/rtc-wm831x.c
+++ b/drivers/rtc/rtc-wm831x.c
@@ -436,7 +436,7 @@
 
 	device_init_wakeup(&pdev->dev, 1);
 
-	wm831x_rtc->rtc = rtc_device_register("wm831x", &pdev->dev,
+	wm831x_rtc->rtc = devm_rtc_device_register(&pdev->dev, "wm831x",
 					      &wm831x_rtc_ops, THIS_MODULE);
 	if (IS_ERR(wm831x_rtc->rtc)) {
 		ret = PTR_ERR(wm831x_rtc->rtc);
@@ -462,10 +462,6 @@
 
 static int wm831x_rtc_remove(struct platform_device *pdev)
 {
-	struct wm831x_rtc *wm831x_rtc = platform_get_drvdata(pdev);
-
-	rtc_device_unregister(wm831x_rtc->rtc);
-
 	return 0;
 }